The significant survival advantage of female sex in nasopharyngeal carcinoma: a propensity-matched analysis

BACKGROUND

Whether females have better survival than males in nasopharyngeal carcinoma is barely acknowledged and the exact explanations remain unknown.

METHODS

Overall, 5929 patients receiving treatment between January 2005 and December 2010 were separately stratified by stage into early and advanced stage groups, and by age into premenopausal (⩽45 years), menopausal (46-54 years) and postmenopausal (⩾55 years) groups. Matched males and females in each group were identified using the propensity score matching method. Differences in disease-free survival (DSS), overall survival (OS), distant metastasis-free survival (DMFS) and locoregional relapse-free survival (LRFS) were estimated by the Kaplan-Meier method and Cox regression model.

RESULTS

Overall, 398, 923, 744, 319 and 313 pairs of males and females were matched in early stage, advanced stage, premenopausal, menopausal and postmenopausal group, respectively. Females showed significant advantage over males across all end points in both early and advanced stage groups (P⩽0.042). However, this advantage persisted at premenopausal age (P⩽0.042), declined during menopause (DMFS, P=0.021; DSS, P=0.100; OS, P=0.693; LRFS, P=0.330) and totally disappeared at postmenopausal age (P⩾0.344).

CONCLUSIONS

Sex significantly affects NPC survival, with a definite female advantage regardless of tumour stage. Intrinsic biologic traits appear to be the exact explanation according to the declining magnitude of sex effect with age.

The effect of BM67 gene deletion on Bombyx mori nuclear polyhedrosis virus replication

Homologs of Bombyx mori nuclear polyhedrosis virus (BmNPV) Bm67 gene ORF67 have been found in the genome of all lepidopteran nuclear polyhedrosis viruses, but their function is still not very clear. In order to analyze it we employed a  bacmid harboring the complete BmNPV genome including the Bm67 gene and expressing infectious virus (wtBacmid) for the construction of its Bm67-deficient variant (Bm67-KO-Bacmid) using the Red recombination system and the Bm67-repaired variant (Bm67-Re-Bacmid) using the Bac-to-Bac system. By transfecting BmN cells with these bacmids we demonstrated that the Bm67-deficient virus did not generate infectious virus, while the repaired virus restored its infectivity, indicating that the Bm67 gene is essential for the formation of infectious budding virus (BV). Electron microscopy of BmN cells transfected with the abovementioned bacmids showed many mature rodshaped virus particles in both wtBacmid- and Bm67-Re-Bacmid-transfected cells but none in Bm67-KO-Bacmid-transfected ones. Moreover, the real-time RT-PCR showed that the deletion of Bm67 from wtBacmid significantly reduced the levels of viral genomic DNA and transcripts of viral early genes dnapol, ie-1 and lef-3 but not those of transcripts of late gene vp39 and very late gene p10. The finding that the Bm67-deficient virus generated reduced levels of infectious virus and transcripts of early dnapol gene but not those of late genes indicates that the Bm67 gene is essential for BmNPV replication.

Correlation between gamma index passing rate and clinical dosimetric difference for pre-treatment 2D and 3D volumetric modulated arc therapy dosimetric verification

OBJECTIVE

To investigate comparatively the percentage gamma passing rate (%GP) of two-dimensional (2D) and three-dimensional (3D) pre-treatment volumetric modulated arc therapy (VMAT) dosimetric verification and their correlation and sensitivity with percentage dosimetric errors (%DE).

METHODS

%GP of 2D and 3D pre-treatment VMAT quality assurance (QA) with different acceptance criteria was obtained by ArcCHECK® (Sun Nuclear Corporation, Melbourne, FL) for 20 patients with nasopharyngeal cancer (NPC) and 20 patients with oesophageal cancer. %DE were calculated from planned dose-volume histogram (DVH) and patients' predicted DVH calculated by 3DVH® software (Sun Nuclear Corporation). Correlation and sensitivity between %GP and %DE were investigated using Pearson's correlation coefficient (r) and receiver operating characteristics (ROCs).

RESULTS

Relatively higher %DE on some DVH-based metrics were observed for both patients with NPC and oesophageal cancer. Except for 2%/2 mm criterion, the average %GPs for all patients undergoing VMAT were acceptable with average rates of 97.11% ± 1.54% and 97.39% ± 1.37% for 2D and 3D 3%/3 mm criteria, respectively. The number of correlations for 3D was higher than that for 2D (21 vs 8). However, the general correlation was still poor for all the analysed metrics (9 out of 26 for 3D 3%/3 mm criterion). The average area under the curve (AUC) of ROCs was 0.66 ± 0.12 and 0.71 ± 0.21 for 2D and 3D evaluations, respectively.

CONCLUSIONS

There is a lack of correlation between %GP and %DE for both 2D and 3D pre-treatment VMAT dosimetric evaluation. DVH-based dose metrics evaluation obtained from 3DVH will provide more useful analysis.

ADVANCES IN KNOWLEDGE

Correlation and sensitivity of %GP with %DE for VMAT QA were studied for the first time.

Filamentation with nonlinear Bessel vortices

We present a new type of ring-shaped filaments featured by stationary nonlinear high-order Bessel solutions to the laser beam propagation equation. Two different regimes are identified by direct numerical simulations of the nonlinear propagation of axicon focused Gaussian beams carrying helicity in a Kerr medium with multiphoton absorption: the stable nonlinear propagation regime corresponds to a slow beam reshaping into one of the stationary nonlinear high-order Bessel solutions, called nonlinear Bessel vortices. The region of existence of nonlinear Bessel vortices is found semi-analytically. The influence of the Kerr nonlinearity and nonlinear losses on the beam shape is presented. Direct numerical simulations highlight the role of attractors played by nonlinear Bessel vortices in the stable propagation regime. Large input powers or small cone angles lead to the unstable propagation regime where nonlinear Bessel vortices break up into an helical multiple filament pattern or a more irregular structure. Nonlinear Bessel vortices are shown to be sufficiently intense to generate a ring-shaped filamentary ionized channel in the medium which is foreseen as opening the way to novel applications in laser material processing of transparent dielectrics.

Lymphoepithelial carcinoma of the salivary gland: morphologic patterns and imaging features on CT and MRI

BACKGROUND AND PURPOSE

Lymphoepithelial carcinoma is a rare salivary gland lesion. We retrospectively reviewed CT and MR imaging features of salivary gland lymphoepithelial carcinoma to determine their imaging features and morphologic patterns.

MATERIALS AND METHODS

The clinical data, CT, and MR imaging findings of 28 patients with histologically proved lymphoepithelial carcinoma of the salivary gland were retrospectively reviewed. Morphologic patterns of the lesions were categorized into 3 types on the basis of margin and shape.

RESULTS

There were 17 men and 11 women with a mean age of 39.3 years; 96.4% of patients were positive for Epstein-Barr virus both on histologic staining and Epstein-Barr virus serology. Tumors were parotid in 18 patients, submandibular in 8 patients, sublingual in 1 patient, and palatal in 1 patient. Most tumors (57.1%) manifested as a partially or ill-defined mass with a lobulated or plaque-like shape. Homogeneous enhancement was found in 16 patients, while heterogeneous enhancement was found in 12, including 4 patients with intratumoral necrosis. Invasion into adjacent structures was found in 5 patients; 60.7% of patients exhibited abnormal lymph nodes, with nodal necrosis in 3 patients.

CONCLUSIONS

The characteristic lobulated or plaque-like shape, with a partially or ill-defined margin, of a salivary gland mass associated with ipsilateral lymphadenopathy may suggest a preoperative diagnosis of lymphoepithelial carcinoma.

Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves by a polarization-insensitive optical parametric amplifier for fiber-nonlinearity-tolerant transmission

We experimentally demonstrate the generation of 1.024-Tb/s Nyquist-WDM phase-conjugated vector twin waves (PCTWs), consisting of eight 128-Gb/s polarization-division-multiplexed QPSK signals and their idlers, by a broadband polarization-insensitive fiber optic parametric amplifier. This novel all-optical signal processing approach to generate WDM-PCTWs enables a 2-fold reduction in the needed optical transmitters as compared to the conventional approach where each idler is generated by a dedicated transmitter. Digital coherent superposition of the twin waves at the receiver enables more than doubled reach in a dispersion-managed transmission link. We further study the impact of polarization-mode dispersion on the performance gain brought by the phase-conjugated twin waves, showing a gain of ~3.8 dB in signal quality factors.

Inhibitory effect of components from Streptomyces species on alpha-glucosidase and alpha-amilase of different origin

The search for the effective and safe a-glucosidase and alpha-amylase inhibitors from Actinomycetaceae being antidiabetic agents is actual problem. Twenty one Streptomyces spp. of soil samples collected from different places of China were screened for the ability to produce this kind of inhibitory activities. Fermentation broth of isolated strains had absorbance between 350-190 nm. The Streptomyces strains PW003, ZG636, and ZG731 were characterized by special absorption at 280, 275, and 400 nm, respectively. Ten of the collected actinomycete strains had the ability to inhibit alpha-glucosidase or/and alpha-amylase and the fermentation broth of the same strain had inhibitory activity varied greatly depending on the enzyme source. In the process to screen the leading compounds used as antidiabetic agents, human alpha-glucosidase and alpha-amylase were revealed as the best used in trail compared with the same enzymes from other sources. Active alpha-glucosidase inhibitor was isolated from Streptomyces strain PW638 fermentation broth and identified as acarviostatin 103 by MS and N MR spectrometry. Its IC50 value was 1.25 and 12.23 microg/mL against human intestinal N-terminal maltase-glucoamylase and human pancreatic alpha-amylase, respectively.